Giardia lamblia, a parasite that until recent years was believed by most physicians to be harmless, now heads the list of the most common intestinal parasitic infections in the United States and some other countries. The parasite causes a diarrheal disease called giardiasis.
The parasite can infect anyone, anyplace, and it causes a variety of intestinal symptoms, such as prolonged diarrhea, abdominal cramps, stomach pain, severe weight loss, fatigue, nausea and flatulence.
Giardiasis can cause malabsorption of nutrients and even retarded growth. More importantly, giardiasis can mimic the symptoms of other conditions such as ulcers and gall bladder attacks. A patient may have a series of costly, needless tests, and even surgery, unless the physician considers the parasite as a possible diagnosis.
Usually the infection can be successfully treated with one of three drugs: Atabrine, Flagyl or furazolidone. However, each of these drugs is known to cause adverse side effects. Until the present invention, no prophylactic drug has been found which can successfully protect against giardiasis. (L. K. Altman, M.D., The New York Times, June 10, 1980).
The present invention relates to the use of a group of benzylidene aminoguanidines which are more active and less toxic than Flagyl (metronidazole) and other commonly used drugs in the treatment of giardiasis in humans. Flagyl is a known carcinogen whereas the benzylidene aminoguanidines have been established as a safe anticoccidial drug.
The benzylidene aminoguanidines and methods of preparation thereof have been disclosed in U.S. Pat. Nos. 3,769,432; 3,901,944; 3,941,825; and 3,992,446, and are herein incorporated by reference.
The utilities disclosed in these patents are essentially (1) control of coccidiosis and (2) preventing or treating malaria in chickens and other domestic animals such as turkeys, sheep, cattle and pigs. The causative microorganisms of coccidiosis are of the genus Eimeria and that of malaria are of the genus Anopheles.